Hyperpigmentation is characterized by an excess production of melanin. One type of hyperpigmentation is local and is viewable as brown spots on the face and back of the hand of people impacted. Hyperpigmentation is caused by excessive exposure to the sun, damage, such as is caused by acne vulgaris, and age. Historically, hyperpigmentation has been treated with hydroquinone, kojic acid, alpha hydroxy acids, azelaic acid, ascorbic acid, tretinoin, topical glucocorticoids, and licorice extract.